CN111414100B - Capacitive touch panel and method of driving the same - Google Patents
Capacitive touch panel and method of driving the same Download PDFInfo
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/0416—Control or interface arrangements specially adapted for digitisers
- G06F3/04166—Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/0416—Control or interface arrangements specially adapted for digitisers
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
- G06F3/0446—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
- G06F2203/041—Indexing scheme relating to G06F3/041 - G06F3/045
- G06F2203/04111—Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
- G06F2203/041—Indexing scheme relating to G06F3/041 - G06F3/045
- G06F2203/04112—Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
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Abstract
A capacitive touch panel includes a plurality of x-ray channels extending in a first direction, a plurality of y-ray channels extending in a second direction different from the first direction, and processing circuitry configured to: a first voltage is applied to the x-ray channels and a second voltage is applied to the y-ray channels, wherein the first voltage and the second voltage have phases opposite to each other and a contact is sensed at least one of the intersections of the plurality of x-ray channels with the plurality of y-ray channels.
Description
Cross Reference to Related Applications
The present application claims priority from korean patent application No.10-2019-0001713 filed in the korean intellectual property office on 1 month 7 of 2019, the disclosure of which is incorporated herein by reference in its entirety.
Technical Field
The present inventive concept relates to a capacitive touch panel and/or a driving method thereof.
Background
In general, a touch screen panel is a screen equipped with a special input device for receiving a touch position when a hand touches the screen. When a person's hand or object touches a character or a specific location on the screen, input data is received directly on the screen so that the touch location is determined, thereby allowing specific processing to be performed by stored software.
In recent years, mobile devices such as smartphones have rapidly become popular. Such mobile devices employ touch sensors to implement various functions. Methods of recognizing touches by a touch sensor can be classified into a resistive film method and a capacitive method. .
A capacitive touch screen panel adopts a method of using electrostatic capacitance of a human body. This method is classified as: a touch recognition method in which a change in resistance and current generated by capacitance of a human body is measured to recognize a touch, and a capacitive touch sensing method in which charged amounts of capacitors are compared with each other to determine whether a contact has been present.
However, when the user using the device or the grounded state of the device used by the user is poor, the accuracy may become unreliable or degraded. For example, when a user places a device such as a smart phone in a bed without holding the smart phone and touching the screen with only a finger, a bedding (non-conductive object) separates the user and the device from the ground, and the user and the device are grounded to each other by holding. The condition that the ground state of the user or the device is poor is called a low ground quality (LGM) condition. In this case, the possibility of touch performance degradation is high.
Disclosure of Invention
Example embodiments of the present inventive concepts provide a capacitive touch panel configured to reduce or prevent sensitivity from being reduced even when a ground state is poor, and a method of driving the capacitive touch panel.
According to some example embodiments of the inventive concepts, a capacitive touch panel includes a plurality of x-ray channels extending in a first direction, a plurality of y-ray channels extending in a second direction different from the first direction, and processing circuitry configured to: a first voltage is applied to the x-ray channels and a second voltage is applied to the y-ray channels, wherein the first voltage and the second voltage have phases opposite to each other and a contact is sensed at least one of the intersections of the plurality of x-ray channels with the plurality of y-ray channels.
According to some example embodiments of the inventive concepts, a capacitive touch panel includes: a plurality of x-ray channels formed in a first direction; a plurality of y-line channels formed in a second direction different from the first direction, the plurality of y-line channels intersecting the plurality of x-line channels to form an intersection, and the intersection comprising a first intersection combination second intersection set; and a processing circuit configured to sense a contact at least one of the intersections, apply a first voltage to the intersections included in the first set of intersections, and apply a second voltage to the intersections included in the second set of intersections, the first voltage and the second voltage having phases opposite to each other.
According to some example embodiments of the inventive concepts, there is provided a method of driving a capacitive touch panel including a plurality of x-ray channels extending in a first direction and a plurality of y-ray channels extending in a second direction different from the first direction, the method including: applying a first voltage to the x-line channel and a second voltage to the y-line channel, the first voltage and the second voltage having phases opposite to each other; and sensing contact at least one of the intersections of the plurality of x-ray channels with the plurality of y-ray channels.
According to some example embodiments of the inventive concepts, there is provided a method of driving a capacitive touch panel including a plurality of x-ray channels extending in a first direction and a plurality of y-ray channels extending in a second direction different from the first direction, the method including: applying a first voltage to the intersections included in the first intersection group and applying a second voltage to the intersections included in the second intersection group; and sensing contact at least one of the intersections of the plurality of x-ray channels with the plurality of y-ray channels.
Drawings
The foregoing and other aspects, features, and advantages of the disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic diagram showing the change in self capacitance of a touch sensor that depends on a touch;
fig. 2 is a schematic view showing a configuration of a line type touch sensor;
FIG. 3 is a schematic diagram illustrating a typical self-capacitance sensing method;
FIG. 4 is a schematic diagram showing Low Ground Mass (LGM) conditions that may occur during sensing of self-capacitance;
fig. 5 is a schematic view illustrating a linear type capacitive touch panel among capacitive touch panels according to some example embodiments of the inventive concepts;
fig. 6 is a schematic view illustrating a dot-type capacitive touch panel among capacitive touch panels according to some example embodiments of the inventive concepts;
fig. 7 is a flowchart illustrating a method of driving a capacitive touch panel according to some example embodiments of the inventive concepts;
fig. 8 is a flowchart illustrating a method of driving a capacitive touch panel according to some example embodiments of the inventive concepts;
fig. 9 is a flowchart illustrating a method of driving a capacitive touch panel according to some example embodiments of the inventive concepts; and
fig. 10 is a flowchart illustrating a method of driving a capacitive touch panel according to some example embodiments of the inventive concepts.
Detailed Description
Hereinafter, some exemplary embodiments of the inventive concept will be described with reference to the accompanying drawings.
As described above, touch performance may be reduced under LGM conditions. This is because a touch sensing driving signal for measuring a capacitance change is coupled to a user's finger (body) to induce a voltage having the same phase as a sensor driving voltage to the user's finger (body), and the induced voltage causes such side effects: unwanted charge is introduced into the readout path of the touch sensor through the coupling capacitance between the touch sensor and the finger, thereby affecting touch performance. Meanwhile, when the grounding state of the user and the equipment is good, the touch sensing driving signal does not cause obvious coupling in the user body.
In particular, in the case of self-capacitance sensing, the touch sensitivity is reduced because the above phenomenon under LGM conditions reduces the magnitude of the voltage applied to the coupling capacitance between the finger and the sensor. The degree to which the sensor driving voltage is induced to the user's body and the degree to which the induced voltage affects the touch sensor vary according to the thickness of the cover window (typically tempered glass or reinforced plastic) between the touch sensor and the finger.
Some example embodiments of the inventive concepts provide a capacitive touch panel and a driving method thereof.
Fig. 1 is a schematic view showing a change in self capacitance of a touch sensor depending on touch, and fig. 2 is a schematic view showing a configuration of a line type touch sensor. Fig. 3 is a schematic diagram illustrating a typical self-capacitance sensing method, and fig. 4 is a schematic diagram illustrating a Low Ground Mass (LGM) condition that may occur during sensing of self-capacitance.
Capacitance is inversely proportional to the distance between the two conductors and directly proportional to the area of the two conductors. As shown in fig. 1, when a conductor 1 such as a finger or a stylus pen approaches a touch sensor electrode, a contact area "a" formed between the finger and the touch sensor electrode causes the self capacitance of the touch sensor electrode to increase when the capacitance 3 is increased. This phenomenon can be used to form a plurality of touch sensor electrode arrays, and the capacitance change of each electrode can be measured to estimate the position where the finger 1 or the like touches the touch panel.
As shown in fig. 2, as a method of forming a plurality of electrode arrays in the touch panel 100, the line sensor array 10 and the line sensor array 20, which are spaced apart from each other by the same distance, may be generally formed to be orthogonal to each other.
Referring to fig. 2, as shown in CM (23,0), there is a mutual capacitance 9, which is a parasitic capacitance formed at the intersection N of the x-line sense channel and the y-line sense channel. The mutual capacitance varies with the approach of the finger and decreases in the opposite direction to the self-capacitance. In addition, as the finger 1 or the like approaches, the amount of change in capacitance varies depending on the shape of the sensor pattern, the structure of the vertical stack, and the like. However, the amount of change in self capacitance tends to be much larger (e.g., about 10 times larger) than the amount of change in mutual capacitance.
Referring to fig. 3, a widely used method of reading a capacitance change of a touch sensor on a touch panel includes: a change in constant voltage is applied to both ends of the capacitance to be measured and the amount of charge generated at this time is measured. The Tx sensing voltage "a" is reduced to be equal to the Rx sensing voltage "b" except for the self capacitances cs_tx and cs_rx to be measured, so that the mutual capacitance Cm2 (parasitic capacitance) does not affect the charge amounts on the read paths Rx2 and OUT 2. Thus, during sensing of the potential across the mutual capacitance Cm2, the potential remains constant.
However, in the LGM condition where the grounded state of the user or the like is poor, the voltage of the finger 1 is affected by the sensor driving voltage.
Referring to fig. 4, the impedance between user 1 and ground 5, denoted by Z, may be about 200 picofarads (pF) under typical use conditions, but Csy and Csx may be only about 1pF. Thus, as can be seen from the following equation (1), the potential of the finger 1 is not significantly affected by the potentials Vx and Vy (e.g., vtx).
Equation (1):
however, when the impedance Z is reduced to a level of a few pF similar to Csy and Csx (such as under LGM conditions), the potential V of the finger 1 B Is affected by Vtx, and a voltage having the same phase as Vtx appears in a low-frequency band (touch sensing frequency (less than 500 KHz) band).
Therefore, the voltage applied to Csx is not Vtx, and is due to the potential V of finger 1 at Vtx B And decreases. As a result, the sensed charge amount decreases from csx×vtx to csx×vtx (Vtx-VB), and the sensing sensitivity may be lowered. Some example embodiments of the inventive concepts propose driving methods to reduce or prevent such sensitivity degradation in LGM states.
Fig. 5 is a schematic view illustrating a line type capacitive touch panel among capacitive touch panels according to some example embodiments of the inventive concepts, and fig. 6 is a schematic view illustrating a dot type capacitive touch panel among capacitive touch panels according to some example embodiments of the inventive concepts.
The capacitive touch panel according to some example embodiments includes a plurality of x-ray channels extending in a first direction, a plurality of y-line channels extending in a second direction different from the first direction, and/or a sensing unit 200 configured to sense contacts occurring at intersections of the plurality of x-ray channels and the plurality of y-line channels. The sensing unit 200 may apply voltages having opposite phases to the x-line channel and the y-line channel to sense the contact.
The sensing unit 200 may be implemented using processing circuitry, such as hardware including logic circuitry; a hardware/software combination such as a processor executing software; or a combination of both. For example, the processing circuitry may more particularly include, but is not limited to, a Central Processing Unit (CPU), an Arithmetic Logic Unit (ALU), a digital signal processor, a microcomputer, a Field Programmable Gate Array (FPGA), a system on a chip (SoC), a programmable logic unit, a microprocessor, an Application Specific Integrated Circuit (ASIC), and the like.
Referring to fig. 5, a capacitive touch panel according to some example embodiments includes a plurality of x-ray channels 10 extending in a first direction and a plurality of y-ray channels 20 extending in a second direction different from the first direction. As described with reference to fig. 3 and 4, etc., contacts occurring at the intersections of the plurality of x-ray channels 10 and the plurality of y-ray channels 20 are sensed.
In the case where the distances between the plurality of x-ray channels 10 and the distances between the plurality of y-ray channels 20 are equal to each other, when an input device such as a finger, a stylus pen, or the like touches the touch panel, the number of x-sensors and the number of y-sensors included in an area overlapping with a contact area of the finger or the like on the touch panel may be substantially the same. Since the self capacitance formed when each sensor overlaps a finger is proportional to the overlap area, csy and Csx are substantially the same.
This relationship is established more accurately because the number of units of incorporated sensors increases as the area where an input device such as a finger, a stylus pen, or the like contacts the touch panel increases. For example, it will be assumed that circles "c" and "d" shown in fig. 5 and 6 are areas where fingers or the like contact the touch panel. As shown in fig. 5 and 6, the distance between the sensors is determined such that three or more sensor lines react during a typical touch. Thus, this condition can be considered to be effective with respect to typical contact.
Returning to fig. 3 and 4, when Vy is applied to self-capacitance sensing using the aforementioned method with the same amplitude and opposite phase as Vx, V B May be set to (0) or close to (0) in the above equation (1). In this case due to voltage V B The amount of charge sensed remains Csx Vtx even in the LGM state without fluctuation by Vtx, regardless of the LGM state. Therefore, sensitivity reduction can be reduced or prevented under LGM conditions. Thus, in a capacitive touch panel according to some example embodiments, the sense isThe sensing unit 200 applies voltages having opposite phases, not the same phase, to the x-line channel and the y-line channel to sense whether a touch exists.
When voltages having opposite phases are applied to the x-line channel and the y-line channel, the voltages across the mutual capacitance Cm will be interchanged. Therefore, the sensitivity may be slightly lowered due to the influence of the mutual capacitance Cm, compared to the case where voltages having the same phase are applied to the x-line channel and the y-line channel. However, since the mutual capacitance Cm varies by only one tenth (1/10) of the self-capacitance variation when the touch panel is touched, the sensitivity degradation caused by the mutual capacitance Cm is significantly lower.
There may be cases where the x-ray sensor and the y-ray sensor are designed to have different unit sensor shapes.
This results in self-capacitances being different from each other (csy+.csx). Even in this case, the same pattern may exist in which the unit sensors are repeatedly arranged at regular intervals. Thus, a relationship of csx=k×csy can be established with respect to a typical touch event in which voltages having the same phase are applied to the x-line channel and the y-line channel regardless of the touch point. For example, the sum of the x-line self capacitances existing at the intersections between the plurality of channels included in the contact region is K times the sum of the y-line self capacitances existing at the plurality of intersections included in the contact region. In some example embodiments, in this case, the sensing unit 200 may apply a voltage to the x-line channel that is 1/k times the absolute value of the voltage applied to the y-line channel. For example, the relationship between the voltage applied to the y-line channel by the sensing unit 200 and the voltage applied to the x-line channel by the sensing unit 200 may be set to vy= - (K Vx), where K is a real number greater than 0.
In this case, the above equation (1) may be formed as shown in the following equation (2) so that the voltage V B Is 0.
Equation (2):
in the case where the plurality of x-ray channels are equally spaced from each other and the plurality of y-ray channels are equally spaced from each other, the spacing of the plurality of x-ray channels may be different from the spacing of the plurality of y-ray channels. In the capacitive touch panel according to some example embodiments, when the interval of the plurality of x-ray channels is K times that of the plurality of y-ray channels, the sensing unit 200 (not shown) may apply a voltage to the y-ray channels, which is K times the absolute value of the voltage applied to the x-ray channels. Therefore, the voltage V can also be made B And 0 in the above equation (2).
In the above-described exemplary embodiments, whether a device including a capacitive touch panel or a user using the device belongs to an LGM state, voltages having opposite phases are applied to an x-ray channel and a y-ray channel to sense a contact. However, in some example embodiments, the sensing unit 200 may sense the contact by including a period in which voltages having the same phase are applied to the x-line channel and the y-line channel in addition to a period in which voltages having opposite phases are applied to the x-line channel and the y-line channel.
According to some example embodiments, the sensing unit 200 may further include a period in which voltages having the same phase and voltages having opposite phases are applied to the x-ray channel and the y-ray channel, for example, only when it is determined that the states of the device including the capacitive touch panel and the user using the device belong to the LGM state, such as only when it is determined that the portion of the human body contacting the panel is affected by the voltages applied by the sensing unit 200, in which the contacts are sensed, not always by additionally setting the periods in which voltages having the same phase and voltages having opposite phases are applied to the x-ray channel and the y-ray channel.
In fig. 5 and the related description, the line type sensing driving method has been described as an example. However, an operation similar to that of the above-described method may be performed in the dot type sensing driving method shown in fig. 6. For example, a capacitive touch panel according to some example embodiments includes a plurality of x-ray channels formed in a first direction, a plurality of y-line channels formed in a second direction different from the first direction, and/or a sensing unit 200 configured to sense contacts occurring at intersections of the plurality of x-ray channels and the plurality of y-line channels. The intersection points include a first intersection point set and a second intersection point set. The sensing unit 200 may apply voltages having opposite phases to the intersections included in the first intersection group and the intersections included in the second intersection group to sense the contact.
Referring to fig. 6, the intersections of the plurality of x-ray channels with the plurality of y-ray channels are defined by a first set of intersections (31, 32, 33, 34, 35, and 36) and a second set of intersections (41, 42, 43, 44, 45, and 46). As shown in fig. 6, the intersections 31, 32, 33, 34, 35, and 36 included in the first intersection group and the intersections 41, 42, 43, 44, 45, and 46 included in the second intersection group may be alternately arranged in the first direction and the second direction.
The sensing unit 200 may apply voltages having opposite phases to the intersections 31, 32, 33, 34, 35, and 36 included in the first intersection group and the intersections 41, 42, 43, 44, 45, and 46 included in the second intersection group so that the potential V of the finger 1 of the user B Zero (0) to sense contact.
Similar to the description already described in connection with fig. 5 and the related description, when the sum of self capacitances existing at the intersections 32, 33, 34, and 36 of the first intersection group included in the contact region is K times the sum of self capacitances existing at the intersections 41, 42, 44, 45, and 46 of the second intersection group included in the contact region, the sensing unit 200 may apply a voltage to the intersections 32, 33, 34, and 36 of the first intersection group to sense the contact, the voltage being 1/K times the absolute value of the voltage applied to the intersections 41, 42, 44, 45, and 46 of the second intersection group.
In some example embodiments, voltages having opposite phases are applied to intersections included in a first intersection point group and intersections included in a second intersection point group to sense a contact, regardless of whether a state of a device including a capacitive touch panel and a user using the device belongs to an LGM state. However, in some example embodiments, the sensing unit 200 may sense a contact by including applying voltages having the same phase to the intersecting points included in the first intersecting point group and the intersecting points included in the second intersecting point group to sense a contact in addition to the period of time in which voltages having opposite phases are applied to the intersecting points included in the first intersecting point group and the intersecting points included in the second intersecting point group to sense a contact.
According to some example embodiments, the sensing unit 200 may further include a period in which the voltages having the same phase and the voltages having opposite phases are not always applied to the intersections included in the first intersection group and the intersections belonging to the second intersection group by additionally setting a period in which the voltages having opposite phases are applied to the intersections included in the first intersection group and the intersections included in the second intersection group only when it is determined that the states of the device including the capacitive touch panel and the user using the device belong to the LGM state, for example, only when it is determined that the portion of the human body contacting the panel is affected by the voltages applied by the sensing unit 200.
Fig. 7 is a flowchart illustrating a method of driving a capacitive touch panel according to some example embodiments of the inventive concepts, and fig. 8 is a flowchart illustrating a method of driving a capacitive touch panel according to some example embodiments of the inventive concepts.
Methods of driving a capacitive touch panel according to some example embodiments may include: in a capacitive touch panel including a plurality of x-ray channels extending in a first direction, a plurality of y-line channels extending in a second direction different from the first direction, and/or a sensing unit 200 configured to sense contacts occurring at intersections of the plurality of x-ray channels and the plurality of y-line channels, a portion of a human body or a stylus is brought into contact with the panel (S100), and voltages having opposite phases are applied to the x-ray channels and the y-line channels by the sensing unit 200 to sense the contacts (S200).
According to some example embodiments, the method may include applying voltages having the same phase to the x-ray channel and the y-line channel to sense the contact (S120), in addition to applying voltages having opposite phases to the x-ray channel and the y-line channel to sense the contact by the sensing unit 200 (S200). Operations S120 and S200 may be performed in reverse order.
According to some example embodiments, as shown in fig. 8, it is determined whether a low-quality (LGM) condition in which a portion of a human body in contact with a panel is affected by a voltage applied by the sensing unit 200 is established (S140). Operation S200 may be performed only when the determination is yes.
Since the method of driving the capacitive touch panel described with reference to fig. 7 and 8 can be understood with reference to fig. 3 to 5 and the corresponding description of the linear capacitive touch panel, the method will be omitted herein to avoid repetitive description.
Fig. 9 is a flowchart illustrating a method of driving a capacitive touch panel according to some example embodiments of the inventive concepts, and fig. 10 is a flowchart illustrating a method of driving a capacitive touch panel according to some example embodiments of the inventive concepts.
Methods of driving a capacitive touch panel according to some example embodiments may include: in a capacitive touch panel including a plurality of x-ray channels extending in a first direction, a plurality of y-ray channels extending in a second direction different from the first direction, and/or a sensing unit 200 configured to sense contact occurring at intersections of the plurality of x-ray channels and the plurality of y-ray channels, a portion of a human body or a stylus is brought into contact with the panel (S300), and voltages having opposite phases are applied to the intersections included in the first intersection group and the intersections included in the second intersection group to sense the contact (S400).
According to some example embodiments, the method may include applying voltages having the same phase to the intersections included in the first intersection group and the intersections included in the second intersection group to sense the contact (S320), in addition to applying voltages having opposite phases to the intersections included in the first intersection group and the intersections included in the second intersection group to sense the contact (S400). Operations S320 and S400 may be performed in reverse order.
According to some example embodiments, as shown in fig. 10, it is determined whether a low-quality (LGM) condition influenced by a voltage applied by the sensing unit 200 to a portion of a human body in contact with a panel is established (S340). Operation S400 may be performed only when the determination is yes.
Since the method of driving the capacitive touch panel described with reference to fig. 9 and 10 can be understood with reference to fig. 3, 4 and 6 and the corresponding description of the linear capacitive touch panel, the method will be omitted herein to avoid repetitive description.
The term "unit" (e.g., "module" or "table" as used in some example embodiments) may refer to both a software entry and a hardware entry, such as a Field Programmable Gate Array (FPGA) or an application-specific integrated circuit (ASIC), as well as a module that performs certain functions. The modules are not intended to be limited to software or hardware items. A module may be configured to be stored on an addressable storage medium and configured to cause one or more processors to function. A module may include entries such as software entries, object-oriented software entries, class entries, and task entries, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables, as will be appreciated by those skilled in the art. The functionality provided for in the items and modules may be combined into a fewer number of items and modules or may be additional divided into additional items and modules. In addition, the items and modules may be implemented to render one or more CPUs in the device.
According to the capacitive touch panel and the driving method thereof, when the grounded state of the user or the device is poor, the touch sensitivity of the capacitive touch sensor can be reduced or prevented from being lowered.
Although a few example embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations may be made without departing from the scope of the inventive concept defined in the appended claims.
Claims (9)
1. A capacitive touch panel, comprising:
a plurality of x-ray channels extending in a first direction;
a plurality of y-line channels extending in a second direction different from the first direction; and
processing circuitry configured to:
a first voltage is applied to the x-ray channel,
applying a second voltage to the y-line channel, the first voltage and the second voltage having the same phase,
determining that a portion of the human body in contact with the capacitive touch panel is affected by the voltage applied by the processing circuit,
switching from applying a first voltage to the x-ray channel to applying a third voltage to the x-ray channel and from applying a second voltage to the y-ray channel to applying a fourth voltage to the y-ray channel in response to determining that the portion of the human body is affected by the voltage, the third voltage and the fourth voltage having opposite phases to each other, an
A contact is sensed at least one of the intersections of the plurality of x-ray channels with the plurality of y-ray channels.
2. The capacitive touch panel of claim 1 wherein,
the spacing between the plurality of x-ray channels is K times the spacing between the plurality of y-ray channels, where K is a real number greater than 0; and is also provided with
The absolute value of the first voltage is equal to K times the absolute value of the second voltage.
3. The capacitive touch panel of claim 1 wherein,
the sum of the x-line self-capacitances present in the intersection points included in the area of the contact is K times the sum of the y-line self-capacitances present in the intersection points included in the area of the contact, where K is a real number greater than 0, and
the absolute value of the first voltage is 1/K times the absolute value of the second voltage.
4. A capacitive touch panel, comprising:
a plurality of x-ray channels formed in a first direction;
a plurality of y-line channels formed in a second direction different from the first direction, the plurality of y-line channels intersecting the plurality of x-line channels to form an intersection, and the intersection comprising a first intersection set and a second intersection set; and
processing circuitry configured to:
a contact at least one of the intersections is sensed,
applying a first voltage to the intersections included in the first intersection group, an
Applying a second voltage to an intersection included in the second intersection group, the first voltage and the second voltage having the same phase,
determining that a portion of the human body in contact with the capacitive touch panel is affected by the voltage applied by the processing circuit,
in response to determining that a portion of the human body is affected by the voltage, switching from applying a first voltage to an intersection included in the first intersection group to applying a third voltage to the intersection included in the first intersection group, and switching from applying a second voltage to an intersection included in the second intersection group to applying a fourth voltage to the intersection included in the second intersection group, the third voltage and the fourth voltage having opposite phases to each other.
5. The capacitive touch panel according to claim 4, wherein the intersecting points included in the first intersecting point group and the intersecting points included in the second intersecting point group are alternately arranged in the first direction and the second direction.
6. The capacitive touch panel of claim 4 wherein,
the first direction and the second direction are perpendicular to each other,
the sum of the x-line self-capacitances present in the intersections included in the first intersection group in the area including the contact is K times the sum of the y-line self-capacitances present in the intersections included in the second intersection group in the area including the contact, where K is a real number greater than 0, and
the absolute value of the first voltage is 1/K times the absolute value of the second voltage.
7. A method of driving a capacitive touch panel including a plurality of x-ray channels extending in a first direction and a plurality of y-ray channels extending in a second direction different from the first direction, the method comprising:
applying a first voltage to the x-ray channel and a second voltage to the y-ray channel, the first voltage and the second voltage having the same phase;
determining that a portion of the human body in contact with the capacitive touch panel is affected by the applied voltage,
switching from applying a first voltage to the x-ray channel to applying a third voltage to the x-ray channel and from applying a second voltage to the y-ray channel to applying a fourth voltage to the y-ray channel in response to determining that the portion of the human body is affected by the voltage, the third and fourth voltages having opposite phases to each other; and
a contact is sensed at least one of the intersections of the plurality of x-ray channels with the plurality of y-ray channels.
8. The method of claim 7, wherein,
the spacing between the plurality of x-ray channels is K times the spacing between the plurality of y-ray channels, where K is a real number greater than 0, and
the absolute value of the first voltage is K times the absolute value of the second voltage.
9. The method of claim 7, wherein,
the sum of the x-line self-capacitances present in the intersection points included in the area of the contact is K times the sum of the y-line self-capacitances present in the intersection points included in the area of the contact, where K is a real number greater than 0, and
the absolute value of the first voltage is 1/K times the absolute value of the second voltage.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020190001713A KR20200085965A (en) | 2019-01-07 | 2019-01-07 | Capacitance touch panel and method for driving capacitance touch panel |
| KR10-2019-0001713 | 2019-01-07 |
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| Publication Number | Publication Date |
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| CN111414100A CN111414100A (en) | 2020-07-14 |
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| CN202010009423.5A Active CN111414100B (en) | 2019-01-07 | 2020-01-06 | Capacitive touch panel and method of driving the same |
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| US (1) | US11782552B2 (en) |
| KR (1) | KR20200085965A (en) |
| CN (1) | CN111414100B (en) |
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| US11592925B1 (en) * | 2021-11-09 | 2023-02-28 | Synaptics Incorporated | Low latency input object detection under low ground mass condition |
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| KR102175786B1 (en) | 2013-12-27 | 2020-11-06 | 엘지디스플레이 주식회사 | Display device with input system |
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- 2019-10-31 US US16/670,367 patent/US11782552B2/en active Active
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| CN105320385A (en) * | 2014-07-30 | 2016-02-10 | Smk株式会社 | Electrostatic capacitance type touch panel and method of detecting input operation position therein |
| CN108242226A (en) * | 2016-12-26 | 2018-07-03 | 硅工厂股份有限公司 | For the device and method thereof of driving panel |
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| KR20200085965A (en) | 2020-07-16 |
| US11782552B2 (en) | 2023-10-10 |
| CN111414100A (en) | 2020-07-14 |
| US20200218421A1 (en) | 2020-07-09 |
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